@media (min-width: 1200px) {  
    .introduce-content{
        margin-top:6.25rem;
        width:100%;
        height:600px;
        background:skyblue;
    }
}

@media (min-width: 768px) and (max-width: 1200px) { 
    .introduce-content{
        margin-top:5rem;
        width:100%;
        height:600px;
        background:skyblue;
    }
}
@media (max-width: 767px) { 	
	
}